Transformer



April 1943" J. 5. SMITH ET AL 7 2,316,370

TRANSFORMER Filed Jan. 5, 1940 "Z0301 Dawson ATTORNEY Patented Apr. 13,1943 TRANSFORMER John S. Smith, Hazel Crest, and Floyd Dawson, ChicagoHeights, 111., assigno-rs to David L.

Tressler, as trustee Application January 5, 1940, Serial No. 312,482

1 Claim.

Our invention relates in general to electrical apparatus and has moreparticular reference to an improved electro-magnetic transformerparticularly well suited for use in electrical power conversion systems.

An important object is to provide improved means adapted to be energizedfrom a uni-directional electrical power source of relatively lowpotential for the delivery of electrical energy at high potential.

Another important object is to provide an improved power transformer; afurther object being to provide a transformer particularly well suitedfor delivering electrical power at relatively high potential from apower source of relatively low potential, said transformer means havinglow potential portions arranged in novel fashion permitting the powertransformation to be accomplished at maximum efliciency.

Another important object is to provide a power transformer having a highpotential winding and a plurality of low potential windings inductivelycoupled with the high potential winding, said low potential windingscomprising conductor coils arranged in parallel interspacedrelationship, whereby the transformer is of minimum over-all size andwherein the inductive relation between each of said low potentialwindings and the high potential winding is substantially identical so asto permit the device to be used at maximum efficiency in a full waverectifier.

Another object of the invention resides in the manner of applying lowpotential windings in a transformer device by winding the severalconductors forming the low potential windings in construction and methodof making a transformer unit in accordance with the present invention.

To illustrate our invention, we have shown on the drawing an electricalsystem H comprising means for delivering electrical energy at relativelyhigh potential by transforming energy derived from a relatively lowpotential source l3, said system including a transformer I9 embodyingthe present invention. It will be obvious, however, that the inventionis not necessarily restricted in all of its aspects to thetransformation of energy from low to high potential, but that thetransformer l9 may have general application other than in the particularsystem herein shown and described.

In the system shown, however, the power source I3 may comprise a storagebattery of the character usually employed in automotive vehicles forignition, lighting, and for energizing electrical equipment as, forinstance, a radio receiver, ventilating fan, horn and the like, forminga part of the vehicle equipment.

The transformer I9 has a high potential winding 2| and low potentialwindings 23 preferably comprising a plurality of sections 25, 21inductively coupled with the winding 2|, the coupling between thewinding 2| and the sections 25 and 2'! being substantially identical. Inthe illustrated embodiment the sections 25, 2'1 of the low potentialwindings are connected together at one end as at 29 and, through asuitable control switch 3|, to one side of the power source l3. Theopposite ends of the winding sections 25 and 21 are connectedrespectively to the stationary contacts 35 and 31 of a circuit changer33 which is preferably a vibrator having, in addition to the stationarycontacts 35 and. 31, a reed 39 suitably anchored in position tooscillate between the stationary contacts 35 and 31 and alternatelyengage the same. The reed 3Q may be, and preferably is, anchored at oneend and electrically connected in any suitable manner, as indicated atAl, with the power source I3, this connection 4| being preferablyaccomplished by grounding the anchored end of the reed and grounding theside of the power source |3 opposite from the switch 3|. The reed isalso provided with an armature 43 in position to be influenced by anactuating coil 45 which in turn is connected in any suitable manner, asbetween one of the stationary contact sets and the power source l3. inorder that the coil 45 may be periodically ener ized, by connection withthe power source, and de-energized as a result of the vibration of thereed. In the illustrated embodiment, the reed actuating coil "45 isconnected between the stationary contact set 31 and the connection 4|.

The reed 39 is preferably positioned so that the armature 43 is normallyoffset with respect to the coil 45 so that, when the apparatus is atrest. the reed engages and makes electrical contact with one or other ofthe stationary contact sets 35, 31, thus placing one of the windings 25,21 in circuit with the power source is. reierably, the reed 39 is thusbiased to engage the contact set which is not connected with the coil45, i. e., the contact set 35 in the illustrated embodiment. Uponclosure of the switch 3|, a surge of electrical current will take placethrough the low potential winding section 25 thus placed in circuit withthe power source. At the same instant the coil 45 will be energized in adirection to draw the reed 39 out of engagement with the contact set 35and project the same into engagement with the contact set 31. It will benoted that the winding section 21 is at all times in circuit with thepower source 3 through the winding 45. However, this winding 45 is ofrelatively high resistance, so that little current may flow initiallythrough the winding section 21. As soon as the reed 39 disengages thecontact set 35, current flow through the winding section 25 will bediscontinued. When the reed engages the contact set 31, however, thehigh resistance winding 45 will be shortcircuited and a relatively largehow of current will be permitted to flow through the winding section 21.As soon as the reed 39 engages the contact set 37, the coil 45 is shortcircuited and becomes deenergized, thereby releasing the armature 43 sothat the reed, under its normal bias, may return toward the contact set35, thus disengaging the contact set 37 and discontinuing the relativelylarge current flow in the winding section 21. In this manner arelatively large current flow may be initiated alternately through thewinding sections 25 and 2! which, due to the inductive relationshipbetween said winding sections and he winding 2 i, will result in thedevelopment of relatively high alternating or iluctuating potentialbetween the opposite ends of the winding 2|. A condenser 38 may beconnected between each of the contact sets 35 and 31 and the reed 39 toreduce arcing at the contacts as the circuits are interrupted.

The development of the relatively high value alternating potential maybe accomplished by connecting the low voltage winding sections 25,

nating frequency of the potential developed in the winding 2| in thearrangement shown in Figure 1 will be approximately double thealternating frequency produced from the arrangement shown in Figure 2,assuming that the vibrating period of the reed 39 is the same in botharrangements. one amplitude of the alternating potential developed fromthe arrangement shown in Figure 1, however, will be somewhat less thanthat of alternating potential developed from the arrangement shown inFigure 2.

One of the features of the power transforming system H resides in theconstruction of the transformer l9. This transformer comprises a core4'! of any suitable or preferred form upon which the high potentialwinding 2| is arranged, preferably as a plurality of layers 49 suitablyinsulated from each other and from the core 41. A layer of insulation 5|is preferably applied upon the winding 49 and the low potential windingsections 25, 21 are applied outwardly of said layer of insulation 5|.The sections 25, 21 each comprise an electrical conductor, the section25 comprising the conductor 55 and the section 21 comprising a conductor51. These conductors are arranged in parallel adjacent relationship andso wound together in place, as clearly illustrated in Figure 3 of thedrawing. Each of the corresponding portions of the conductors 55, 5!occupies parallel adjacent positions, and the inductive relationship ofboth sections 25 and 21, with respect to the high potential winding 2|,is substantially identical. The conductors 55, 51 may be arranged toform a plurality of layers 59, as clearly shown in Figure 3 of thedrawing, each layer insulated from the other by insulation 60.

It will thus be seen that the winding sections 25 and 2'! havesubstantial identical inductive relationship with the winding 2| andwith each other. Consequently, the wave portions induced in the winding2| by the winding 25 will be substantially identical with the waveportion induced by the winding 21. Likewise, if employed as a step downtransformer, substantially identical wave forms may be generated in thewindings 25 and 21 by energizing the winding 2|. In this respect, theinvention is not necessarily restricted to low potential primary windingsections, but the invention embraces a plurality of high potentialwinding sections having substantially identical inductive coupling witha low potential winding.

In the illustrated embodiment, the transformer is arranged in the systemto deliver alternating current at high potential between the ends of thewinding 2|, but, of course, the winding 2| may be associated withrectifying means if it be desired to obtain uni-directional power athigh potential.

While the winding 2| is shown wound upon the core 41, with the windings25 and 21 in overlying relationship, it is obvious that the invention isnot necessarily restricted to such relationship but embraces anyarrangement in which corresponding portions of the several sections ofone winding have identical relationship with the other winding.

Various useful applications of the transformer herein disclosed will besuggested, and it should be obvious that the invention is notnecessarily limited to the use of the transformer in any particularcombination.

It is thought that the invention and its numerous attendant advantageswill be fully understood from the foregoing description, and it isobvious that numerous changes may be made in the form, construction andarrangement of the parts without departing from the spirit or. scope ofthe invention or sacrificing vits attendant advantages, the form hereindescribed being a preferred embodiment for the purpose of exemplifyingour invention.

The invention is hereby claimed as follows:

A transformer comprising a winding and a plurality of separate coilsinductively coupled with said winding, said coils comprising separateconductors arranged in parallel side-by-side relationship and disposedin turns inductivelycoupled with the winding, whereby the inductiverelationship between the winding and one coil is substantially identicalto the inductive relationship between the winding and another coil, theturns of one coil being interspersed between the turns of another coil,the turns of said coils being arranged in concentric layers.

JOHN S. SMITH. FLOYD DAWSON.

